1. Field of the invention
The present invention relates to a process for the insertion of a supplementary video information set outside a main image of 4/3 format on a television tube of 16/9 format.
2. Description of the prior art
Since a short time ago, image tubes of 16/9 format have been available on the market. These tubes were developed with a view to high-definition applications. Thus, it is possible to envisage with immediate effect the equipping of television receivers with this type of tube, especially television receivers the architecture of which has been constructed so as to be compatible with future standards. Nevertheless, all currently transmitted programs are transmitted in 4/3 format. Thus, in order to be able to display a video image of 4/3 format on a 16/9 tube it is necessary to process this image in order to eliminate the problems of distortion or anamorphosis in the course of the display. Various processings may be envisaged. Thus, in the case of an image of "cinemascope" type it is possible to envisage the enlarging of the image vertically in such a manner as to reduce the black bands. On the other hand, if the image is displayed while maintaining the initial format, a part of the screen is left free.